From: Francesco Dolcini francesco.dolcini@toradex.com
[ Upstream commit 3666aad8185af8d0ce164fd3c4974235417d6d0b ]
Correct computation of TXTAGOCNT register.
This register must be set to a value that ensure that the TTA-GO period = (4 x TLPX)
with the actual value of TTA-GO being
4 x (TXTAGOCNT + 1) x (HSByteClk cycle)
Fixes: ff1ca6397b1d ("drm/bridge: Add tc358768 driver") Signed-off-by: Francesco Dolcini francesco.dolcini@toradex.com Reviewed-by: Robert Foss rfoss@kernel.org Signed-off-by: Robert Foss rfoss@kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20230427142934.55435-8-frances... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/bridge/tc358768.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/tc358768.c b/drivers/gpu/drm/bridge/tc358768.c index e3f456bfb90c1..d8209433d5f43 100644 --- a/drivers/gpu/drm/bridge/tc358768.c +++ b/drivers/gpu/drm/bridge/tc358768.c @@ -796,7 +796,7 @@ static void tc358768_bridge_pre_enable(struct drm_bridge *bridge)
/* TXTAGOCNT[26:16] RXTASURECNT[10:0] */ val = tc358768_to_ns((lptxcnt + 1) * dsibclk_nsk * 4); - val = tc358768_ns_to_cnt(val, dsibclk_nsk) - 1; + val = tc358768_ns_to_cnt(val, dsibclk_nsk) / 4 - 1; val2 = tc358768_ns_to_cnt(tc358768_to_ns((lptxcnt + 1) * dsibclk_nsk), dsibclk_nsk) - 2; val = val << 16 | val2;